Conventionally, so-called a multi-fuel internal combustion engine operated using plural types of fuels with different properties is known. For example, Patent Document 1 shown below discloses a multi-fuel internal combustion engine configured such that a low octane number fuel is injected into a mixture gas of a high octane number fuel which is injected into an intake air port and the mixture gas of the high octane number fuel is flame propagation combusted using the spontaneous combustion of the low octane number fuel as a starting point and describes that knocking can be prevented by the flame propagation combustion because a time until the combustion is completed can be reduced by increasing a combustion speed. Patent Document 2 shown below discloses a multi-fuel internal combustion engine which can be operated using a fuel selected by a driver from many types of fuels such as gasoline, diesel oil, and ethanol. Further, the Patent Document 2 describes also a multi-fuel internal combustion engine which is operated in a flame ignition mode when an engine load is lower than a predetermined load and is operated in a compressed self-ignition diffusive combustion mode when the engine load is higher than the predetermined load. Further, Patent Document 3 shown below describes a multi-fuel internal combustion engine which is operated using a mixed fuel of gasoline and diesel oil.    Patent Document 1: Japanese Patent Application Laid-open No. 2004-197660    Patent Document 2: Japanese Patent Application Laid-open No. 2004-245126    Patent Document 3: Japanese Patent Application Laid-open No. 9-68061